| 1 | S & P Energy | Benbrook, TX 76126 | Oil & Gas Operator | Oct 1994 |
| 2 | S N D Energy Company, Inc. | Kilgore, TX 75662 | Oil & Gas Operator | Oct 2025 |
| 3 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Oct 2025 |
| 4 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 5 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 6 | Samson Lone Star LP | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2007 |
| 7 | Samson Lone Star, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2025 |
| 8 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 9 | SDG Operating Company, Inc | Tyler, TX 75701 | Oil & Gas Operator | Oct 2025 |
| 10 | Seal Exploration, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Dec 2006 |
| 11 | Sellers Lease Service, Inc. | Flatonia, TX 78941 | Oil & Gas Operator | Oct 2025 |
| 12 | Share Petroleum Corp. | Mabank, TX 75147 | Oil Operator | Oct 2025 |
| 13 | Shelby Production Co. | Kilgore, TX 75663 | Oil & Gas Operator | Mar 2009 |
| 14 | Shidler, Mark L., Inc. | Houston, TX 77055 | Oil & Gas Operator | Oct 2025 |
| 15 | Sklar-Tex L.L.C. | Shreveport, LA 71101 | Oil & Gas Operator | Apr 2001 |
| 16 | Smith Oil Company | Smackover, AR 71762 | Oil Operator | Jan 2025 |
| 17 | Southwest Operating, Inc.-Tyler | Tyler, TX 75701 | Oil & Gas Operator | Oct 2025 |
| 18 | Spence, Ralph Oil Company, Inc. | Tyler, TX 75701 | Oil & Gas Operator | Jun 2023 |
| 19 | Stonewall Production Company Inc | Tyler, TX 75702 | Oil & Gas Operator | Aug 2009 |